spi/s3c64xx: Flush FIFOs prior to cleaning up transfer
spi/s3c64xx: Flush FIFOs prior to cleaning up transfer

Ensure that the FIFOs are fully drained before we deassert /CS or do any
delays that have been requested in order to ensure that the behaviour
visible on the bus matches that which was requested by the caller.

Signed-off-by: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs